/*
 * Copyright (c) 2011 Seoul National University
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Jung Ho Ahn  ( gajh@snu.ac.kr )
 *          Sungwoo Choo ( choos@snu.ac.kr )
 *
 */

#include <pthread.h>
#include "BarrierUtil.h"

int barrier_init(barrier_t *barrier, int needed)
{
  barrier->needed = needed;
  barrier->called = 0;
  pthread_mutex_init(&barrier->mutex, NULL);
  pthread_cond_init(&barrier->cond, NULL);
  return 0;
}


int barrier_destroy(barrier_t *barrier)
{
  pthread_mutex_destroy(&barrier->mutex);
  pthread_cond_destroy(&barrier->cond);
  return 0;
}


int barrier_wait(barrier_t *barrier)
{
  pthread_mutex_lock(&barrier->mutex);
  barrier->called++;
  if (barrier->called == barrier->needed)
  {
    barrier->called = 0;
    pthread_cond_broadcast(&barrier->cond);
  }
  else
  {
    pthread_cond_wait(&barrier->cond, &barrier->mutex);
  }
  pthread_mutex_unlock(&barrier->mutex);
  return 0;
}

